xref: /netbsd/sys/arch/arm/xscale/pxa2x0_dmac.c (revision a8a5c538)
1 /*	$NetBSD: pxa2x0_dmac.c,v 1.14 2018/09/03 16:29:24 riastradh Exp $	*/
2 
3 /*
4  * Copyright (c) 2003, 2005 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Steve C. Woodford for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed for the NetBSD Project by
20  *	Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include "opt_pxa2x0_dmac.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/device.h>
43 #include <sys/kernel.h>
44 #include <sys/kmem.h>
45 #include <sys/queue.h>
46 
47 #include <uvm/uvm_param.h>	/* For PAGE_SIZE */
48 
49 #include <machine/intr.h>
50 #include <sys/bus.h>
51 
52 #include <dev/dmover/dmovervar.h>
53 
54 #include <arm/xscale/pxa2x0reg.h>
55 #include <arm/xscale/pxa2x0var.h>
56 #include <arm/xscale/pxa2x0cpu.h>
57 
58 #include <arm/xscale/pxa2x0_dmac.h>
59 
60 #include "locators.h"
61 
62 #undef DMAC_N_PRIORITIES
63 #ifndef PXA2X0_DMAC_FIXED_PRIORITY
64 #define DMAC_N_PRIORITIES 3
65 #define DMAC_PRI(p)   (p)
66 #else
67 #define DMAC_N_PRIORITIES 1
68 #define DMAC_PRI(p)   (0)
69 #endif
70 
71 struct dmac_desc {
72 	SLIST_ENTRY(dmac_desc) d_link;
73 	struct pxa2x0_dma_desc *d_desc;
74 	paddr_t d_desc_pa;
75 };
76 
77 /*
78  * This is used to maintain state for an in-progress transfer.
79  * It tracks the current DMA segment, and offset within the segment
80  * in the case where we had to split a request into several DMA
81  * operations due to a shortage of DMAC descriptors.
82  */
83 struct dmac_desc_segs {
84 	bus_dma_segment_t *ds_curseg;		/* Current segment */
85 	u_int ds_nsegs;				/* Remaining segments */
86 	bus_size_t ds_offset;			/* Offset within current seg */
87 };
88 
89 SIMPLEQ_HEAD(dmac_xfer_state_head, dmac_xfer_state);
90 
91 struct dmac_xfer_state {
92 	struct dmac_xfer dxs_xfer;
93 #define	dxs_cookie	dxs_xfer.dx_cookie
94 #define	dxs_done	dxs_xfer.dx_done
95 #define	dxs_priority	dxs_xfer.dx_priority
96 #define	dxs_peripheral	dxs_xfer.dx_peripheral
97 #define	dxs_flow	dxs_xfer.dx_flow
98 #define	dxs_dev_width	dxs_xfer.dx_dev_width
99 #define	dxs_burst_size	dxs_xfer.dx_burst_size
100 #define	dxs_loop_notify	dxs_xfer.dx_loop_notify
101 #define	dxs_desc	dxs_xfer.dx_desc
102 	SIMPLEQ_ENTRY(dmac_xfer_state) dxs_link;
103 	SLIST_HEAD(, dmac_desc) dxs_descs;
104 	struct dmac_xfer_state_head *dxs_queue;
105 	u_int dxs_channel;
106 #define	DMAC_NO_CHANNEL	(~0)
107 	uint32_t dxs_dcmd;
108 	struct dmac_desc_segs dxs_segs[2];
109 	bool dxs_misaligned_flag;
110 };
111 
112 
113 #if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
114 /*
115  * This structure is used to maintain state for the dmover(9) backend
116  * part of the driver. We can have a number of concurrent dmover
117  * requests in progress at any given time. The exact number is given
118  * by the PXA2X0_DMAC_DMOVER_CONCURRENCY compile-time constant. One of
119  * these structures is allocated for each concurrent request.
120  */
121 struct dmac_dmover_state {
122 	LIST_ENTRY(dmac_dmover_state) ds_link;	/* List of idle dmover chans */
123 	struct pxadmac_softc *ds_sc;		/* Uplink to pxadmac softc */
124 	struct dmover_request *ds_current;	/* Current dmover request */
125 	struct dmac_xfer_state ds_xfer;
126 	bus_dmamap_t ds_src_dmap;
127 	bus_dmamap_t ds_dst_dmap;
128 /*
129  * There is no inherent size limit in the DMA engine.
130  * The following limit is somewhat arbitrary.
131  */
132 #define	DMAC_DMOVER_MAX_XFER	(8*1024*1024)
133 #if 0
134 /* This would require 16KB * 2 just for segments... */
135 #define DMAC_DMOVER_NSEGS	((DMAC_DMOVER_MAX_XFER / PAGE_SIZE) + 1)
136 #else
137 #define DMAC_DMOVER_NSEGS	512		/* XXX: Only enough for 2MB */
138 #endif
139 	bus_dma_segment_t ds_zero_seg;		/* Used for zero-fill ops */
140 	void *ds_zero_va;
141 	bus_dma_segment_t ds_fill_seg;		/* Used for fill8 ops */
142 	void *ds_fill_va;
143 
144 #define	ds_src_addr_hold	ds_xfer.dxs_desc[DMAC_DESC_SRC].xd_addr_hold
145 #define	ds_dst_addr_hold	ds_xfer.dxs_desc[DMAC_DESC_DST].xd_addr_hold
146 #define	ds_src_burst		ds_xfer.dxs_desc[DMAC_DESC_SRC].xd_burst_size
147 #define	ds_dst_burst		ds_xfer.dxs_desc[DMAC_DESC_DST].xd_burst_size
148 #define	ds_src_dma_segs		ds_xfer.dxs_desc[DMAC_DESC_SRC].xd_dma_segs
149 #define	ds_dst_dma_segs		ds_xfer.dxs_desc[DMAC_DESC_DST].xd_dma_segs
150 #define	ds_src_nsegs		ds_xfer.dxs_desc[DMAC_DESC_SRC].xd_nsegs
151 #define	ds_dst_nsegs		ds_xfer.dxs_desc[DMAC_DESC_DST].xd_nsegs
152 };
153 
154 /*
155  * Overall dmover(9) backend state
156  */
157 struct dmac_dmover {
158 	struct dmover_backend dd_backend;
159 	int dd_busy;
160 	LIST_HEAD(, dmac_dmover_state) dd_free;
161 	struct dmac_dmover_state dd_state[PXA2X0_DMAC_DMOVER_CONCURRENCY];
162 };
163 #endif
164 
165 struct pxadmac_softc {
166 	device_t sc_dev;
167 	bus_space_tag_t sc_bust;
168 	bus_dma_tag_t sc_dmat;
169 	bus_space_handle_t sc_bush;
170 	void *sc_irqcookie;
171 
172 	/*
173 	 * Queue of pending requests, per priority
174 	 */
175 	struct dmac_xfer_state_head sc_queue[DMAC_N_PRIORITIES];
176 
177 	/*
178 	 * Queue of pending requests, per peripheral
179 	 */
180 	struct {
181 		struct dmac_xfer_state_head sp_queue;
182 		u_int sp_busy;
183 	} sc_periph[DMAC_N_PERIPH];
184 
185 	/*
186 	 * Active requests, per channel.
187 	 */
188 	struct dmac_xfer_state *sc_active[DMAC_N_CHANNELS];
189 
190 	/*
191 	 * Channel Priority Allocation
192 	 */
193 	struct {
194 		uint8_t p_first;
195 		uint8_t p_pri[DMAC_N_CHANNELS];
196 	} sc_prio[DMAC_N_PRIORITIES];
197 #define	DMAC_PRIO_END		(~0)
198 	uint8_t sc_channel_priority[DMAC_N_CHANNELS];
199 
200 	/*
201 	 * DMA descriptor management
202 	 */
203 	bus_dmamap_t sc_desc_map;
204 	bus_dma_segment_t sc_segs;
205 #define	DMAC_N_DESCS	((PAGE_SIZE * 2) / sizeof(struct pxa2x0_dma_desc))
206 #define	DMAC_DESCS_SIZE	(DMAC_N_DESCS * sizeof(struct pxa2x0_dma_desc))
207 	struct dmac_desc sc_all_descs[DMAC_N_DESCS];
208 	u_int sc_free_descs;
209 	SLIST_HEAD(, dmac_desc) sc_descs;
210 
211 #if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
212 	/*
213 	 * dmover(9) backend state
214 	 */
215 	struct dmac_dmover sc_dmover;
216 #endif
217 };
218 
219 static int	pxadmac_match(device_t, cfdata_t, void *);
220 static void	pxadmac_attach(device_t, device_t, void *);
221 
222 CFATTACH_DECL_NEW(pxadmac, sizeof(struct pxadmac_softc),
223     pxadmac_match, pxadmac_attach, NULL, NULL);
224 
225 static struct pxadmac_softc *pxadmac_sc;
226 
227 static void dmac_start(struct pxadmac_softc *, dmac_priority_t);
228 static int dmac_continue_xfer(struct pxadmac_softc *, struct dmac_xfer_state *);
229 static u_int dmac_channel_intr(struct pxadmac_softc *, u_int);
230 static int dmac_intr(void *);
231 
232 #if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
233 static void dmac_dmover_attach(struct pxadmac_softc *);
234 static void dmac_dmover_process(struct dmover_backend *);
235 static void dmac_dmover_run(struct dmover_backend *);
236 static void dmac_dmover_done(struct dmac_xfer *, int);
237 #endif
238 
239 static inline uint32_t
dmac_reg_read(struct pxadmac_softc * sc,int reg)240 dmac_reg_read(struct pxadmac_softc *sc, int reg)
241 {
242 
243 	return (bus_space_read_4(sc->sc_bust, sc->sc_bush, reg));
244 }
245 
246 static inline void
dmac_reg_write(struct pxadmac_softc * sc,int reg,uint32_t val)247 dmac_reg_write(struct pxadmac_softc *sc, int reg, uint32_t val)
248 {
249 
250 	bus_space_write_4(sc->sc_bust, sc->sc_bush, reg, val);
251 }
252 
253 static inline int
dmac_allocate_channel(struct pxadmac_softc * sc,dmac_priority_t priority,u_int * chanp)254 dmac_allocate_channel(struct pxadmac_softc *sc, dmac_priority_t priority,
255     u_int *chanp)
256 {
257 	u_int channel;
258 
259 	KDASSERT((u_int)priority < DMAC_N_PRIORITIES);
260 
261 	if ((channel = sc->sc_prio[priority].p_first) == DMAC_PRIO_END)
262 		return (-1);
263 	sc->sc_prio[priority].p_first = sc->sc_prio[priority].p_pri[channel];
264 
265 	*chanp = channel;
266 	return (0);
267 }
268 
269 static inline void
dmac_free_channel(struct pxadmac_softc * sc,dmac_priority_t priority,u_int channel)270 dmac_free_channel(struct pxadmac_softc *sc, dmac_priority_t priority,
271     u_int channel)
272 {
273 
274 	KDASSERT((u_int)priority < DMAC_N_PRIORITIES);
275 
276 	sc->sc_prio[priority].p_pri[channel] = sc->sc_prio[priority].p_first;
277 	sc->sc_prio[priority].p_first = channel;
278 }
279 
280 static int
pxadmac_match(device_t parent,cfdata_t cf,void * aux)281 pxadmac_match(device_t parent, cfdata_t cf, void *aux)
282 {
283 	struct pxaip_attach_args *pxa = aux;
284 
285 	if (pxadmac_sc || pxa->pxa_addr != PXA2X0_DMAC_BASE ||
286 	    pxa->pxa_intr != PXA2X0_INT_DMA)
287 		return (0);
288 
289 	pxa->pxa_size = PXA2X0_DMAC_SIZE;
290 
291 	return (1);
292 }
293 
294 static void
pxadmac_attach(device_t parent,device_t self,void * aux)295 pxadmac_attach(device_t parent, device_t self, void *aux)
296 {
297 	struct pxadmac_softc *sc = device_private(self);
298 	struct pxaip_attach_args *pxa = aux;
299 	struct pxa2x0_dma_desc *dd;
300 	int i, nsegs;
301 
302 	sc->sc_dev = self;
303 	sc->sc_bust = pxa->pxa_iot;
304 	sc->sc_dmat = pxa->pxa_dmat;
305 
306 	aprint_normal(": DMA Controller\n");
307 
308 	if (bus_space_map(sc->sc_bust, pxa->pxa_addr, pxa->pxa_size, 0,
309 	    &sc->sc_bush)) {
310 		aprint_error_dev(self, "Can't map registers!\n");
311 		return;
312 	}
313 
314 	pxadmac_sc = sc;
315 
316 	/*
317 	 * Make sure the DMAC is quiescent
318 	 */
319 	for (i = 0; i < DMAC_N_CHANNELS; i++) {
320 		dmac_reg_write(sc, DMAC_DCSR(i), 0);
321 		dmac_reg_write(sc, DMAC_DRCMR(i), 0);
322 		sc->sc_active[i] = NULL;
323 	}
324 	if (!CPU_IS_PXA270)
325 		dmac_reg_write(sc, DMAC_DINT,
326 		    dmac_reg_read(sc, DMAC_DINT) & DMAC_DINT_MASK);
327 
328 	/*
329 	 * Initialise the request queues
330 	 */
331 	for (i = 0; i < DMAC_N_PRIORITIES; i++)
332 		SIMPLEQ_INIT(&sc->sc_queue[i]);
333 
334 	/*
335 	 * Initialise the request queues
336 	 */
337 	for (i = 0; i < DMAC_N_PERIPH; i++) {
338 		sc->sc_periph[i].sp_busy = 0;
339 		SIMPLEQ_INIT(&sc->sc_periph[i].sp_queue);
340 	}
341 
342 	/*
343 	 * Initialise the channel priority metadata
344 	 */
345 	memset(sc->sc_prio, DMAC_PRIO_END, sizeof(sc->sc_prio));
346 	for (i = 0; i < DMAC_N_CHANNELS; i++) {
347 #if (DMAC_N_PRIORITIES > 1)
348 		if (i <= 3)
349 			dmac_free_channel(sc, DMAC_PRIORITY_HIGH, i);
350 		else
351 		if (i <= 7)
352 			dmac_free_channel(sc, DMAC_PRIORITY_MED, i);
353 		else
354 			dmac_free_channel(sc, DMAC_PRIORITY_LOW, i);
355 #else
356 		dmac_free_channel(sc, DMAC_PRIORITY_NORMAL, i);
357 #endif
358 	}
359 
360 	/*
361 	 * Initialise DMA descriptors and associated metadata
362 	 */
363 	if (bus_dmamem_alloc(sc->sc_dmat, DMAC_DESCS_SIZE, DMAC_DESCS_SIZE, 0,
364 	    &sc->sc_segs, 1, &nsegs, BUS_DMA_NOWAIT))
365 		panic("dmac_pxaip_attach: bus_dmamem_alloc failed");
366 
367 	if (bus_dmamem_map(sc->sc_dmat, &sc->sc_segs, 1, DMAC_DESCS_SIZE,
368 	    (void *)&dd, BUS_DMA_COHERENT|BUS_DMA_NOCACHE))
369 		panic("dmac_pxaip_attach: bus_dmamem_map failed");
370 
371 	if (bus_dmamap_create(sc->sc_dmat, DMAC_DESCS_SIZE, 1,
372 	    DMAC_DESCS_SIZE, 0, BUS_DMA_NOWAIT, &sc->sc_desc_map))
373 		panic("dmac_pxaip_attach: bus_dmamap_create failed");
374 
375 	if (bus_dmamap_load(sc->sc_dmat, sc->sc_desc_map, (void *)dd,
376 	    DMAC_DESCS_SIZE, NULL, BUS_DMA_NOWAIT))
377 		panic("dmac_pxaip_attach: bus_dmamap_load failed");
378 
379 	SLIST_INIT(&sc->sc_descs);
380 	sc->sc_free_descs = DMAC_N_DESCS;
381 	for (i = 0; i < DMAC_N_DESCS; i++, dd++) {
382 		SLIST_INSERT_HEAD(&sc->sc_descs, &sc->sc_all_descs[i], d_link);
383 		sc->sc_all_descs[i].d_desc = dd;
384 		sc->sc_all_descs[i].d_desc_pa =
385 		    sc->sc_segs.ds_addr + (sizeof(struct pxa2x0_dma_desc) * i);
386 	}
387 
388 	sc->sc_irqcookie = pxa2x0_intr_establish(pxa->pxa_intr, IPL_BIO,
389 	    dmac_intr, sc);
390 	KASSERT(sc->sc_irqcookie != NULL);
391 
392 #if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
393 	dmac_dmover_attach(sc);
394 #endif
395 }
396 
397 #if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
398 /*
399  * We support the following dmover(9) operations
400  */
401 static const struct dmover_algdesc dmac_dmover_algdescs[] = {
402 	{DMOVER_FUNC_ZERO, NULL, 0},	/* Zero-fill */
403 	{DMOVER_FUNC_FILL8, NULL, 0},	/* Fill with 8-bit immediate value */
404 	{DMOVER_FUNC_COPY, NULL, 1}	/* Copy */
405 };
406 #define	DMAC_DMOVER_ALGDESC_COUNT \
407 	(sizeof(dmac_dmover_algdescs) / sizeof(dmac_dmover_algdescs[0]))
408 
409 static void
dmac_dmover_attach(struct pxadmac_softc * sc)410 dmac_dmover_attach(struct pxadmac_softc *sc)
411 {
412 	struct dmac_dmover *dd = &sc->sc_dmover;
413 	struct dmac_dmover_state *ds;
414 	int i, dummy;
415 
416 	/*
417 	 * Describe ourselves to the dmover(9) code
418 	 */
419 	dd->dd_backend.dmb_name = "pxadmac";
420 	dd->dd_backend.dmb_speed = 100*1024*1024;	/* XXX */
421 	dd->dd_backend.dmb_cookie = sc;
422 	dd->dd_backend.dmb_algdescs = dmac_dmover_algdescs;
423 	dd->dd_backend.dmb_nalgdescs = DMAC_DMOVER_ALGDESC_COUNT;
424 	dd->dd_backend.dmb_process = dmac_dmover_process;
425 	dd->dd_busy = 0;
426 	LIST_INIT(&dd->dd_free);
427 
428 	for (i = 0; i < PXA2X0_DMAC_DMOVER_CONCURRENCY; i++) {
429 		ds = &dd->dd_state[i];
430 		ds->ds_sc = sc;
431 		ds->ds_current = NULL;
432 		ds->ds_xfer.dxs_cookie = ds;
433 		ds->ds_xfer.dxs_done = dmac_dmover_done;
434 		ds->ds_xfer.dxs_priority = DMAC_PRIORITY_NORMAL;
435 		ds->ds_xfer.dxs_peripheral = DMAC_PERIPH_NONE;
436 		ds->ds_xfer.dxs_flow = DMAC_FLOW_CTRL_NONE;
437 		ds->ds_xfer.dxs_dev_width = DMAC_DEV_WIDTH_DEFAULT;
438 		ds->ds_xfer.dxs_burst_size = DMAC_BURST_SIZE_8;	/* XXX */
439 		ds->ds_xfer.dxs_loop_notify = DMAC_DONT_LOOP;
440 		ds->ds_src_addr_hold = false;
441 		ds->ds_dst_addr_hold = false;
442 		ds->ds_src_nsegs = 0;
443 		ds->ds_dst_nsegs = 0;
444 		LIST_INSERT_HEAD(&dd->dd_free, ds, ds_link);
445 
446 		/*
447 		 * Create dma maps for both source and destination buffers.
448 		 */
449 		if (bus_dmamap_create(sc->sc_dmat, DMAC_DMOVER_MAX_XFER,
450 				DMAC_DMOVER_NSEGS, DMAC_DMOVER_MAX_XFER,
451 				0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
452 				&ds->ds_src_dmap) ||
453 		    bus_dmamap_create(sc->sc_dmat, DMAC_DMOVER_MAX_XFER,
454 				DMAC_DMOVER_NSEGS, DMAC_DMOVER_MAX_XFER,
455 				0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
456 				&ds->ds_dst_dmap)) {
457 			panic("dmac_dmover_attach: bus_dmamap_create failed");
458 		}
459 
460 		/*
461 		 * Allocate some dma memory to be used as source buffers
462 		 * for the zero-fill and fill-8 operations. We only need
463 		 * small buffers here, since we set up the DMAC source
464 		 * descriptor with 'ds_addr_hold' set to true.
465 		 */
466 		if (bus_dmamem_alloc(sc->sc_dmat, arm_pcache.dcache_line_size,
467 				arm_pcache.dcache_line_size, 0,
468 				&ds->ds_zero_seg, 1, &dummy, BUS_DMA_NOWAIT) ||
469 		    bus_dmamem_alloc(sc->sc_dmat, arm_pcache.dcache_line_size,
470 				arm_pcache.dcache_line_size, 0,
471 				&ds->ds_fill_seg, 1, &dummy, BUS_DMA_NOWAIT)) {
472 			panic("dmac_dmover_attach: bus_dmamem_alloc failed");
473 		}
474 
475 		if (bus_dmamem_map(sc->sc_dmat, &ds->ds_zero_seg, 1,
476 				arm_pcache.dcache_line_size, &ds->ds_zero_va,
477 				BUS_DMA_NOWAIT) ||
478 		    bus_dmamem_map(sc->sc_dmat, &ds->ds_fill_seg, 1,
479 				arm_pcache.dcache_line_size, &ds->ds_fill_va,
480 				BUS_DMA_NOWAIT)) {
481 			panic("dmac_dmover_attach: bus_dmamem_map failed");
482 		}
483 
484 		/*
485 		 * Make sure the zero-fill source buffer really is zero filled
486 		 */
487 		memset(ds->ds_zero_va, 0, arm_pcache.dcache_line_size);
488 	}
489 
490 	dmover_backend_register(&sc->sc_dmover.dd_backend);
491 }
492 
493 static void
dmac_dmover_process(struct dmover_backend * dmb)494 dmac_dmover_process(struct dmover_backend *dmb)
495 {
496 	struct pxadmac_softc *sc = dmb->dmb_cookie;
497 	int s = splbio();
498 
499 	/*
500 	 * If the backend is currently idle, go process the queue.
501 	 */
502 	if (sc->sc_dmover.dd_busy == 0)
503 		dmac_dmover_run(&sc->sc_dmover.dd_backend);
504 	splx(s);
505 }
506 
507 static void
dmac_dmover_run(struct dmover_backend * dmb)508 dmac_dmover_run(struct dmover_backend *dmb)
509 {
510 	struct dmover_request *dreq;
511 	struct pxadmac_softc *sc;
512 	struct dmac_dmover *dd;
513 	struct dmac_dmover_state *ds;
514 	size_t len_src, len_dst;
515 	int rv;
516 
517 	sc = dmb->dmb_cookie;
518 	dd = &sc->sc_dmover;
519 	sc->sc_dmover.dd_busy = 1;
520 
521 	/*
522 	 * As long as we can queue up dmover requests...
523 	 */
524 	while ((dreq = TAILQ_FIRST(&dmb->dmb_pendreqs)) != NULL &&
525 	    (ds = LIST_FIRST(&dd->dd_free)) != NULL) {
526 		/*
527 		 * Pull the request off the queue, mark it 'running',
528 		 * and make it 'current'.
529 		 */
530 		dmover_backend_remque(dmb, dreq);
531 		dreq->dreq_flags |= DMOVER_REQ_RUNNING;
532 		LIST_REMOVE(ds, ds_link);
533 		ds->ds_current = dreq;
534 
535 		switch (dreq->dreq_outbuf_type) {
536 		case DMOVER_BUF_LINEAR:
537 			len_dst = dreq->dreq_outbuf.dmbuf_linear.l_len;
538 			break;
539 		case DMOVER_BUF_UIO:
540 			len_dst = dreq->dreq_outbuf.dmbuf_uio->uio_resid;
541 			break;
542 		default:
543 			goto error;
544 		}
545 
546 		/*
547 		 * Fix up the appropriate DMA 'source' buffer
548 		 */
549 		if (dreq->dreq_assignment->das_algdesc->dad_ninputs) {
550 			struct uio *uio;
551 			/*
552 			 * This is a 'copy' operation.
553 			 * Load up the specified source buffer
554 			 */
555 			switch (dreq->dreq_inbuf_type) {
556 			case DMOVER_BUF_LINEAR:
557 				len_src= dreq->dreq_inbuf[0].dmbuf_linear.l_len;
558 				if (len_src != len_dst)
559 					goto error;
560 				if (bus_dmamap_load(sc->sc_dmat,ds->ds_src_dmap,
561 				    dreq->dreq_inbuf[0].dmbuf_linear.l_addr,
562 				    len_src, NULL,
563 				    BUS_DMA_NOWAIT | BUS_DMA_STREAMING |
564 				    BUS_DMA_READ))
565 					goto error;
566 				break;
567 
568 			case DMOVER_BUF_UIO:
569 				uio = dreq->dreq_inbuf[0].dmbuf_uio;
570 				len_src = uio->uio_resid;
571 				if (uio->uio_rw != UIO_WRITE ||
572 				    len_src != len_dst)
573 					goto error;
574 				if (bus_dmamap_load_uio(sc->sc_dmat,
575 				    ds->ds_src_dmap, uio,
576 				    BUS_DMA_NOWAIT | BUS_DMA_STREAMING |
577 				    BUS_DMA_READ))
578 					goto error;
579 				break;
580 
581 			default:
582 				goto error;
583 			}
584 
585 			ds->ds_src_addr_hold = false;
586 		} else
587 		if (dreq->dreq_assignment->das_algdesc->dad_name ==
588 		    DMOVER_FUNC_ZERO) {
589 			/*
590 			 * Zero-fill operation.
591 			 * Simply load up the pre-zeroed source buffer
592 			 */
593 			if (bus_dmamap_load(sc->sc_dmat, ds->ds_src_dmap,
594 			    ds->ds_zero_va, arm_pcache.dcache_line_size, NULL,
595 			    BUS_DMA_NOWAIT | BUS_DMA_STREAMING | BUS_DMA_READ))
596 				goto error;
597 
598 			ds->ds_src_addr_hold = true;
599 		} else
600 		if (dreq->dreq_assignment->das_algdesc->dad_name ==
601 		    DMOVER_FUNC_FILL8) {
602 			/*
603 			 * Fill-8 operation.
604 			 * Initialise our fill-8 buffer, and load it up.
605 			 *
606 			 * XXX: Experiment with exactly how much of the
607 			 * source buffer needs to be filled. Particularly WRT
608 			 * burst size (which is hardcoded to 8 for dmover).
609 			 */
610 			memset(ds->ds_fill_va, dreq->dreq_immediate[0],
611 			    arm_pcache.dcache_line_size);
612 
613 			if (bus_dmamap_load(sc->sc_dmat, ds->ds_src_dmap,
614 			    ds->ds_fill_va, arm_pcache.dcache_line_size, NULL,
615 			    BUS_DMA_NOWAIT | BUS_DMA_STREAMING | BUS_DMA_READ))
616 				goto error;
617 
618 			ds->ds_src_addr_hold = true;
619 		} else {
620 			goto error;
621 		}
622 
623 		/*
624 		 * Now do the same for the destination buffer
625 		 */
626 		switch (dreq->dreq_outbuf_type) {
627 		case DMOVER_BUF_LINEAR:
628 			if (bus_dmamap_load(sc->sc_dmat, ds->ds_dst_dmap,
629 			    dreq->dreq_outbuf.dmbuf_linear.l_addr,
630 			    len_dst, NULL,
631 			    BUS_DMA_NOWAIT | BUS_DMA_STREAMING | BUS_DMA_WRITE))
632 				goto error_unload_src;
633 			break;
634 
635 		case DMOVER_BUF_UIO:
636 			if (dreq->dreq_outbuf.dmbuf_uio->uio_rw != UIO_READ)
637 				goto error_unload_src;
638 			if (bus_dmamap_load_uio(sc->sc_dmat, ds->ds_dst_dmap,
639 			    dreq->dreq_outbuf.dmbuf_uio,
640 			    BUS_DMA_NOWAIT | BUS_DMA_STREAMING | BUS_DMA_WRITE))
641 				goto error_unload_src;
642 			break;
643 
644 		default:
645 		error_unload_src:
646 			bus_dmamap_unload(sc->sc_dmat, ds->ds_src_dmap);
647 		error:
648 			dreq->dreq_error = EINVAL;
649 			dreq->dreq_flags |= DMOVER_REQ_ERROR;
650 			ds->ds_current = NULL;
651 			LIST_INSERT_HEAD(&dd->dd_free, ds, ds_link);
652 			dmover_done(dreq);
653 			continue;
654 		}
655 
656 		/*
657 		 * The last step before shipping the request off to the
658 		 * DMAC driver is to sync the dma maps.
659 		 */
660 		bus_dmamap_sync(sc->sc_dmat, ds->ds_src_dmap, 0,
661 		    ds->ds_src_dmap->dm_mapsize, BUS_DMASYNC_PREWRITE);
662 		ds->ds_src_dma_segs = ds->ds_src_dmap->dm_segs;
663 		ds->ds_src_nsegs = ds->ds_src_dmap->dm_nsegs;
664 
665 		bus_dmamap_sync(sc->sc_dmat, ds->ds_dst_dmap, 0,
666 		    ds->ds_dst_dmap->dm_mapsize, BUS_DMASYNC_PREREAD);
667 		ds->ds_dst_dma_segs = ds->ds_dst_dmap->dm_segs;
668 		ds->ds_dst_nsegs = ds->ds_dst_dmap->dm_nsegs;
669 
670 		/*
671 		 * Hand the request over to the dmac section of the driver.
672 		 */
673 		if ((rv = pxa2x0_dmac_start_xfer(&ds->ds_xfer.dxs_xfer)) != 0) {
674 			bus_dmamap_unload(sc->sc_dmat, ds->ds_src_dmap);
675 			bus_dmamap_unload(sc->sc_dmat, ds->ds_dst_dmap);
676 			dreq->dreq_error = rv;
677 			dreq->dreq_flags |= DMOVER_REQ_ERROR;
678 			ds->ds_current = NULL;
679 			LIST_INSERT_HEAD(&dd->dd_free, ds, ds_link);
680 			dmover_done(dreq);
681 		}
682 	}
683 
684 	/* All done */
685 	sc->sc_dmover.dd_busy = 0;
686 }
687 
688 static void
dmac_dmover_done(struct dmac_xfer * dx,int error)689 dmac_dmover_done(struct dmac_xfer *dx, int error)
690 {
691 	struct dmac_dmover_state *ds = dx->dx_cookie;
692 	struct pxadmac_softc *sc = ds->ds_sc;
693 	struct dmover_request *dreq = ds->ds_current;
694 
695 	/*
696 	 * A dmover(9) request has just completed.
697 	 */
698 
699 	KDASSERT(dreq != NULL);
700 
701 	/*
702 	 * Sync and unload the DMA maps
703 	 */
704 	bus_dmamap_sync(sc->sc_dmat, ds->ds_src_dmap, 0,
705 	    ds->ds_src_dmap->dm_mapsize, BUS_DMASYNC_POSTREAD);
706 	bus_dmamap_sync(sc->sc_dmat, ds->ds_dst_dmap, 0,
707 	    ds->ds_dst_dmap->dm_mapsize, BUS_DMASYNC_POSTWRITE);
708 
709 	bus_dmamap_unload(sc->sc_dmat, ds->ds_src_dmap);
710 	bus_dmamap_unload(sc->sc_dmat, ds->ds_dst_dmap);
711 
712 	ds->ds_current = NULL;
713 	LIST_INSERT_HEAD(&sc->sc_dmover.dd_free, ds, ds_link);
714 
715 	/*
716 	 * Record the completion status of the transfer
717 	 */
718 	if (error) {
719 		dreq->dreq_error = error;
720 		dreq->dreq_flags |= DMOVER_REQ_ERROR;
721 	} else {
722 		if (dreq->dreq_outbuf_type == DMOVER_BUF_UIO)
723 			dreq->dreq_outbuf.dmbuf_uio->uio_resid = 0;
724 		if (dreq->dreq_assignment->das_algdesc->dad_ninputs &&
725 		    dreq->dreq_inbuf_type == DMOVER_BUF_UIO)
726 			dreq->dreq_inbuf[0].dmbuf_uio->uio_resid = 0;
727 	}
728 
729 	/*
730 	 * Done!
731 	 */
732 	dmover_done(dreq);
733 
734 	/*
735 	 * See if we can start some more dmover(9) requests.
736 	 *
737 	 * Note: We're already at splbio() here.
738 	 */
739 	if (sc->sc_dmover.dd_busy == 0)
740 		dmac_dmover_run(&sc->sc_dmover.dd_backend);
741 }
742 #endif
743 
744 struct dmac_xfer *
pxa2x0_dmac_allocate_xfer(void)745 pxa2x0_dmac_allocate_xfer(void)
746 {
747 	struct dmac_xfer_state *dxs;
748 
749 	dxs = kmem_alloc(sizeof(*dxs), KM_SLEEP);
750 
751 	return ((struct dmac_xfer *)dxs);
752 }
753 
754 void
pxa2x0_dmac_free_xfer(struct dmac_xfer * dx)755 pxa2x0_dmac_free_xfer(struct dmac_xfer *dx)
756 {
757 	struct dmac_xfer_state *dxs = (struct dmac_xfer_state *)dx;
758 
759 	/*
760 	 * XXX: Should verify the DMAC is not actively using this
761 	 * structure before freeing...
762 	 */
763 	kmem_free(dxs, sizeof(*dxs));
764 }
765 
766 static inline int
dmac_validate_desc(struct dmac_xfer_desc * xd,size_t * psize,bool * misaligned_flag)767 dmac_validate_desc(struct dmac_xfer_desc *xd, size_t *psize,
768     bool *misaligned_flag)
769 {
770 	bus_dma_segment_t *dma_segs = xd->xd_dma_segs;
771 	bus_addr_t periph_end;
772 	bus_size_t align;
773 	size_t size;
774 	int i, nsegs = xd->xd_nsegs;
775 
776 	/*
777 	 * Make sure the transfer parameters are acceptable.
778 	 */
779 
780 	if (xd->xd_addr_hold &&
781 	    (nsegs != 1 || dma_segs[0].ds_len == 0))
782 		return (EINVAL);
783 
784 	periph_end = CPU_IS_PXA270 ? PXA270_PERIPH_END : PXA250_PERIPH_END;
785 	for (i = 0, size = 0; i < nsegs; i++) {
786 		if (dma_segs[i].ds_addr >= PXA2X0_PERIPH_START &&
787 		    dma_segs[i].ds_addr + dma_segs[i].ds_len < periph_end)
788 			/* Internal Peripherals. */
789 			align = 0x03;
790 		else /* Companion-Chip/External Peripherals/External Memory. */
791 			align = 0x07;
792 		/*
793 		 * XXXX:
794 		 * Also PXA27x has more constraints by pairs Source/Target.
795 		 */
796 
797 		if (dma_segs[i].ds_addr & align) {
798 			if (!CPU_IS_PXA270)
799 				return (EFAULT);
800 			*misaligned_flag = true;
801 		}
802 		size += dma_segs[i].ds_len;
803 	}
804 
805 	*psize = size;
806 	return (0);
807 }
808 
809 static inline int
dmac_init_desc(struct dmac_desc_segs * ds,struct dmac_xfer_desc * xd,size_t * psize,bool * misaligned_flag)810 dmac_init_desc(struct dmac_desc_segs *ds, struct dmac_xfer_desc *xd,
811     size_t *psize, bool *misaligned_flag)
812 {
813 	int err;
814 
815 	if ((err = dmac_validate_desc(xd, psize, misaligned_flag)))
816 		return (err);
817 
818 	ds->ds_curseg = xd->xd_dma_segs;
819 	ds->ds_nsegs = xd->xd_nsegs;
820 	ds->ds_offset = 0;
821 	return (0);
822 }
823 
824 int
pxa2x0_dmac_start_xfer(struct dmac_xfer * dx)825 pxa2x0_dmac_start_xfer(struct dmac_xfer *dx)
826 {
827 	struct pxadmac_softc *sc = pxadmac_sc;
828 	struct dmac_xfer_state *dxs = (struct dmac_xfer_state *)dx;
829 	struct dmac_xfer_desc *src, *dst;
830 	size_t size;
831 	int err, s;
832 
833 	if (dxs->dxs_peripheral != DMAC_PERIPH_NONE &&
834 	    dxs->dxs_peripheral >= DMAC_N_PERIPH)
835 		return (EINVAL);
836 
837 	src = &dxs->dxs_desc[DMAC_DESC_SRC];
838 	dst = &dxs->dxs_desc[DMAC_DESC_DST];
839 
840 	dxs->dxs_misaligned_flag = false;
841 
842 	if ((err = dmac_init_desc(&dxs->dxs_segs[DMAC_DESC_SRC], src, &size,
843 	    &dxs->dxs_misaligned_flag)))
844 		return (err);
845 	if (src->xd_addr_hold == false &&
846 	    dxs->dxs_loop_notify != DMAC_DONT_LOOP &&
847 	    (size % dxs->dxs_loop_notify) != 0)
848 		return (EINVAL);
849 
850 	if ((err = dmac_init_desc(&dxs->dxs_segs[DMAC_DESC_DST], dst, &size,
851 	    &dxs->dxs_misaligned_flag)))
852 		return (err);
853 	if (dst->xd_addr_hold == false &&
854 	    dxs->dxs_loop_notify != DMAC_DONT_LOOP &&
855 	    (size % dxs->dxs_loop_notify) != 0)
856 		return (EINVAL);
857 
858 	SLIST_INIT(&dxs->dxs_descs);
859 	dxs->dxs_channel = DMAC_NO_CHANNEL;
860 	dxs->dxs_dcmd = (((uint32_t)dxs->dxs_dev_width) << DCMD_WIDTH_SHIFT) |
861 	    (((uint32_t)dxs->dxs_burst_size) << DCMD_SIZE_SHIFT);
862 
863 	switch (dxs->dxs_flow) {
864 	case DMAC_FLOW_CTRL_NONE:
865 		break;
866 	case DMAC_FLOW_CTRL_SRC:
867 		dxs->dxs_dcmd |= DCMD_FLOWSRC;
868 		break;
869 	case DMAC_FLOW_CTRL_DEST:
870 		dxs->dxs_dcmd |= DCMD_FLOWTRG;
871 		break;
872 	}
873 
874 	if (src->xd_addr_hold == false)
875 		dxs->dxs_dcmd |= DCMD_INCSRCADDR;
876 	if (dst->xd_addr_hold == false)
877 		dxs->dxs_dcmd |= DCMD_INCTRGADDR;
878 
879 	s = splbio();
880 	if (dxs->dxs_peripheral == DMAC_PERIPH_NONE ||
881 	    sc->sc_periph[dxs->dxs_peripheral].sp_busy == 0) {
882 		dxs->dxs_queue = &sc->sc_queue[DMAC_PRI(dxs->dxs_priority)];
883 		SIMPLEQ_INSERT_TAIL(dxs->dxs_queue, dxs, dxs_link);
884 		if (dxs->dxs_peripheral != DMAC_PERIPH_NONE)
885 			sc->sc_periph[dxs->dxs_peripheral].sp_busy++;
886 		dmac_start(sc, DMAC_PRI(dxs->dxs_priority));
887 	} else {
888 		dxs->dxs_queue = &sc->sc_periph[dxs->dxs_peripheral].sp_queue;
889 		SIMPLEQ_INSERT_TAIL(dxs->dxs_queue, dxs, dxs_link);
890 		sc->sc_periph[dxs->dxs_peripheral].sp_busy++;
891 	}
892 	splx(s);
893 
894 	return (0);
895 }
896 
897 void
pxa2x0_dmac_abort_xfer(struct dmac_xfer * dx)898 pxa2x0_dmac_abort_xfer(struct dmac_xfer *dx)
899 {
900 	struct pxadmac_softc *sc = pxadmac_sc;
901 	struct dmac_xfer_state *ndxs, *dxs = (struct dmac_xfer_state *)dx;
902 	struct dmac_desc *desc, *ndesc;
903 	struct dmac_xfer_state_head *queue;
904 	uint32_t rv;
905 	int s, timeout, need_start = 0;
906 
907 	s = splbio();
908 
909 	queue = dxs->dxs_queue;
910 
911 	if (dxs->dxs_channel == DMAC_NO_CHANNEL) {
912 		/*
913 		 * The request has not yet started, or it has already
914 		 * completed. If the request is not on a queue, just
915 		 * return.
916 		 */
917 		if (queue == NULL) {
918 			splx(s);
919 			return;
920 		}
921 
922 		dxs->dxs_queue = NULL;
923 		SIMPLEQ_REMOVE(queue, dxs, dmac_xfer_state, dxs_link);
924 	} else {
925 		/*
926 		 * The request is in progress. This is a bit trickier.
927 		 */
928 		dmac_reg_write(sc, DMAC_DCSR(dxs->dxs_channel), 0);
929 
930 		for (timeout = 5000; timeout; timeout--) {
931 			rv = dmac_reg_read(sc, DMAC_DCSR(dxs->dxs_channel));
932 			if (rv & DCSR_STOPSTATE)
933 				break;
934 			delay(1);
935 		}
936 
937 		if ((rv & DCSR_STOPSTATE) == 0)
938 			panic(
939 			   "pxa2x0_dmac_abort_xfer: channel %d failed to abort",
940 			    dxs->dxs_channel);
941 
942 		/*
943 		 * Free resources allocated to the request
944 		 */
945 		for (desc = SLIST_FIRST(&dxs->dxs_descs); desc; desc = ndesc) {
946 			ndesc = SLIST_NEXT(desc, d_link);
947 			SLIST_INSERT_HEAD(&sc->sc_descs, desc, d_link);
948 			sc->sc_free_descs++;
949 		}
950 
951 		sc->sc_active[dxs->dxs_channel] = NULL;
952 		dmac_free_channel(sc, DMAC_PRI(dxs->dxs_priority),
953 		    dxs->dxs_channel);
954 
955 		if (dxs->dxs_peripheral != DMAC_PERIPH_NONE)
956 			dmac_reg_write(sc, DMAC_DRCMR(dxs->dxs_peripheral), 0);
957 
958 		need_start = 1;
959 		dxs->dxs_queue = NULL;
960 	}
961 
962 	if (dxs->dxs_peripheral == DMAC_PERIPH_NONE ||
963 	    sc->sc_periph[dxs->dxs_peripheral].sp_busy-- == 1 ||
964 	    queue == &sc->sc_periph[dxs->dxs_peripheral].sp_queue)
965 		goto out;
966 
967 	/*
968 	 * We've just removed the current item for this
969 	 * peripheral, and there is at least one more
970 	 * pending item waiting. Make it current.
971 	 */
972 	ndxs = SIMPLEQ_FIRST(&sc->sc_periph[dxs->dxs_peripheral].sp_queue);
973 	dxs = ndxs;
974 	KDASSERT(dxs != NULL);
975 	SIMPLEQ_REMOVE_HEAD(&sc->sc_periph[dxs->dxs_peripheral].sp_queue,
976 	    dxs_link);
977 
978 	dxs->dxs_queue = &sc->sc_queue[DMAC_PRI(dxs->dxs_priority)];
979 	SIMPLEQ_INSERT_TAIL(dxs->dxs_queue, dxs, dxs_link);
980 	need_start = 1;
981 
982 	/*
983 	 * Try to start any pending requests with the same
984 	 * priority.
985 	 */
986 out:
987 	if (need_start)
988 		dmac_start(sc, DMAC_PRI(dxs->dxs_priority));
989 	splx(s);
990 }
991 
992 static void
dmac_start(struct pxadmac_softc * sc,dmac_priority_t priority)993 dmac_start(struct pxadmac_softc *sc, dmac_priority_t priority)
994 {
995 	struct dmac_xfer_state *dxs;
996 	u_int channel;
997 
998 	while (sc->sc_free_descs &&
999 	    (dxs = SIMPLEQ_FIRST(&sc->sc_queue[priority])) != NULL &&
1000 	    dmac_allocate_channel(sc, priority, &channel) == 0) {
1001 		/*
1002 		 * Yay, got some descriptors, a transfer request, and
1003 		 * an available DMA channel.
1004 		 */
1005 		KDASSERT(sc->sc_active[channel] == NULL);
1006 		SIMPLEQ_REMOVE_HEAD(&sc->sc_queue[priority], dxs_link);
1007 
1008 		/* set DMA alignment register */
1009 		if (CPU_IS_PXA270) {
1010 			uint32_t dalgn;
1011 
1012 			dalgn = dmac_reg_read(sc, DMAC_DALGN);
1013 			dalgn &= ~(1U << channel);
1014 			if (dxs->dxs_misaligned_flag)
1015 				dalgn |= (1U << channel);
1016 			dmac_reg_write(sc, DMAC_DALGN, dalgn);
1017 		}
1018 
1019 		dxs->dxs_channel = channel;
1020 		sc->sc_active[channel] = dxs;
1021 		(void) dmac_continue_xfer(sc, dxs);
1022 		/*
1023 		 * XXX: Deal with descriptor allocation failure for loops
1024 		 */
1025 	}
1026 }
1027 
1028 static int
dmac_continue_xfer(struct pxadmac_softc * sc,struct dmac_xfer_state * dxs)1029 dmac_continue_xfer(struct pxadmac_softc *sc, struct dmac_xfer_state *dxs)
1030 {
1031 	struct dmac_desc *desc, *prev_desc;
1032 	struct pxa2x0_dma_desc *dd;
1033 	struct dmac_desc_segs *src_ds, *dst_ds;
1034 	struct dmac_xfer_desc *src_xd, *dst_xd;
1035 	bus_dma_segment_t *src_seg, *dst_seg;
1036 	bus_addr_t src_mem_addr, dst_mem_addr;
1037 	bus_size_t src_size, dst_size, this_size;
1038 
1039 	desc = NULL;
1040 	prev_desc = NULL;
1041 	dd = NULL;
1042 	src_ds = &dxs->dxs_segs[DMAC_DESC_SRC];
1043 	dst_ds = &dxs->dxs_segs[DMAC_DESC_DST];
1044 	src_xd = &dxs->dxs_desc[DMAC_DESC_SRC];
1045 	dst_xd = &dxs->dxs_desc[DMAC_DESC_DST];
1046 	SLIST_INIT(&dxs->dxs_descs);
1047 
1048 	/*
1049 	 * As long as the source/destination buffers have DMA segments,
1050 	 * and we have free descriptors, build a DMA chain.
1051 	 */
1052 	while (src_ds->ds_nsegs && dst_ds->ds_nsegs && sc->sc_free_descs) {
1053 		src_seg = src_ds->ds_curseg;
1054 		src_mem_addr = src_seg->ds_addr + src_ds->ds_offset;
1055 		if (src_xd->xd_addr_hold == false &&
1056 		    dxs->dxs_loop_notify != DMAC_DONT_LOOP)
1057 			src_size = dxs->dxs_loop_notify;
1058 		else
1059 			src_size = src_seg->ds_len - src_ds->ds_offset;
1060 
1061 		dst_seg = dst_ds->ds_curseg;
1062 		dst_mem_addr = dst_seg->ds_addr + dst_ds->ds_offset;
1063 		if (dst_xd->xd_addr_hold == false &&
1064 		    dxs->dxs_loop_notify != DMAC_DONT_LOOP)
1065 			dst_size = dxs->dxs_loop_notify;
1066 		else
1067 			dst_size = dst_seg->ds_len - dst_ds->ds_offset;
1068 
1069 		/*
1070 		 * We may need to split a source or destination segment
1071 		 * across two or more DMAC descriptors.
1072 		 */
1073 		while (src_size && dst_size &&
1074 		    (desc = SLIST_FIRST(&sc->sc_descs)) != NULL) {
1075 			SLIST_REMOVE_HEAD(&sc->sc_descs, d_link);
1076 			sc->sc_free_descs--;
1077 
1078 			/*
1079 			 * Decide how much data we're going to transfer
1080 			 * using this DMAC descriptor.
1081 			 */
1082 			if (src_xd->xd_addr_hold)
1083 				this_size = dst_size;
1084 			else
1085 			if (dst_xd->xd_addr_hold)
1086 				this_size = src_size;
1087 			else
1088 				this_size = uimin(dst_size, src_size);
1089 
1090 			/*
1091 			 * But clamp the transfer size to the DMAC
1092 			 * descriptor's maximum.
1093 			 */
1094 			this_size = uimin(this_size, DCMD_LENGTH_MASK & ~0x1f);
1095 
1096 			/*
1097 			 * Fill in the DMAC descriptor
1098 			 */
1099 			dd = desc->d_desc;
1100 			dd->dd_dsadr = src_mem_addr;
1101 			dd->dd_dtadr = dst_mem_addr;
1102 			dd->dd_dcmd = dxs->dxs_dcmd | this_size;
1103 
1104 			/*
1105 			 * Link it into the chain
1106 			 */
1107 			if (prev_desc) {
1108 				SLIST_INSERT_AFTER(prev_desc, desc, d_link);
1109 				prev_desc->d_desc->dd_ddadr = desc->d_desc_pa;
1110 			} else {
1111 				SLIST_INSERT_HEAD(&dxs->dxs_descs, desc,
1112 				    d_link);
1113 			}
1114 			prev_desc = desc;
1115 
1116 			/*
1117 			 * Update the source/destination pointers
1118 			 */
1119 			if (src_xd->xd_addr_hold == false) {
1120 				src_size -= this_size;
1121 				src_ds->ds_offset += this_size;
1122 				if (src_ds->ds_offset == src_seg->ds_len) {
1123 					KDASSERT(src_size == 0);
1124 					src_ds->ds_curseg = ++src_seg;
1125 					src_ds->ds_offset = 0;
1126 					src_ds->ds_nsegs--;
1127 				} else
1128 					src_mem_addr += this_size;
1129 			}
1130 
1131 			if (dst_xd->xd_addr_hold == false) {
1132 				dst_size -= this_size;
1133 				dst_ds->ds_offset += this_size;
1134 				if (dst_ds->ds_offset == dst_seg->ds_len) {
1135 					KDASSERT(dst_size == 0);
1136 					dst_ds->ds_curseg = ++dst_seg;
1137 					dst_ds->ds_offset = 0;
1138 					dst_ds->ds_nsegs--;
1139 				} else
1140 					dst_mem_addr += this_size;
1141 			}
1142 		}
1143 
1144 		if (dxs->dxs_loop_notify != DMAC_DONT_LOOP) {
1145 			/*
1146 			 * We must be able to allocate descriptors for the
1147 			 * entire loop. Otherwise, return them to the pool
1148 			 * and bail.
1149 			 */
1150 			if (desc == NULL) {
1151 				struct dmac_desc *ndesc;
1152 				for (desc = SLIST_FIRST(&dxs->dxs_descs);
1153 				    desc; desc = ndesc) {
1154 					ndesc = SLIST_NEXT(desc, d_link);
1155 					SLIST_INSERT_HEAD(&sc->sc_descs, desc,
1156 					    d_link);
1157 					sc->sc_free_descs++;
1158 				}
1159 
1160 				return (0);
1161 			}
1162 
1163 			KASSERT(dd != NULL);
1164 			dd->dd_dcmd |= DCMD_ENDIRQEN;
1165 		}
1166 	}
1167 
1168 	/*
1169 	 * Did we manage to build a chain?
1170 	 * If not, just return.
1171 	 */
1172 	if (dd == NULL)
1173 		return (0);
1174 
1175 	if (dxs->dxs_loop_notify == DMAC_DONT_LOOP) {
1176 		dd->dd_dcmd |= DCMD_ENDIRQEN;
1177 		dd->dd_ddadr = DMAC_DESC_LAST;
1178 	} else
1179 		dd->dd_ddadr = SLIST_FIRST(&dxs->dxs_descs)->d_desc_pa;
1180 
1181 	if (dxs->dxs_peripheral != DMAC_PERIPH_NONE) {
1182 		dmac_reg_write(sc, DMAC_DRCMR(dxs->dxs_peripheral),
1183 		    dxs->dxs_channel | DRCMR_MAPVLD);
1184 	}
1185 	dmac_reg_write(sc, DMAC_DDADR(dxs->dxs_channel),
1186 	    SLIST_FIRST(&dxs->dxs_descs)->d_desc_pa);
1187 	dmac_reg_write(sc, DMAC_DCSR(dxs->dxs_channel),
1188 	    DCSR_ENDINTR | DCSR_RUN);
1189 
1190 	return (1);
1191 }
1192 
1193 static u_int
dmac_channel_intr(struct pxadmac_softc * sc,u_int channel)1194 dmac_channel_intr(struct pxadmac_softc *sc, u_int channel)
1195 {
1196 	struct dmac_xfer_state *dxs;
1197 	struct dmac_desc *desc, *ndesc;
1198 	uint32_t dcsr;
1199 	u_int rv = 0;
1200 
1201 	dcsr = dmac_reg_read(sc, DMAC_DCSR(channel));
1202 	dmac_reg_write(sc, DMAC_DCSR(channel), dcsr);
1203 	if (dmac_reg_read(sc, DMAC_DCSR(channel)) & DCSR_STOPSTATE)
1204 		dmac_reg_write(sc, DMAC_DCSR(channel), dcsr & ~DCSR_RUN);
1205 
1206 	if ((dxs = sc->sc_active[channel]) == NULL) {
1207 		aprint_error_dev(sc->sc_dev,
1208 		    "Stray DMAC interrupt for unallocated channel %d\n",
1209 		    channel);
1210 		return (0);
1211 	}
1212 
1213 	/*
1214 	 * Clear down the interrupt in the DMA Interrupt Register
1215 	 */
1216 	if (!CPU_IS_PXA270)
1217 		dmac_reg_write(sc, DMAC_DINT, (1u << channel));
1218 
1219 	/*
1220 	 * If this is a looping request, invoke the 'done' callback and
1221 	 * return immediately.
1222 	 */
1223 	if (dxs->dxs_loop_notify != DMAC_DONT_LOOP &&
1224 	    (dcsr & DCSR_BUSERRINTR) == 0) {
1225 		(dxs->dxs_done)(&dxs->dxs_xfer, 0);
1226 		return (0);
1227 	}
1228 
1229 	/*
1230 	 * Free the descriptors allocated to the completed transfer
1231 	 *
1232 	 * XXX: If there is more data to transfer in this request,
1233 	 * we could simply reuse some or all of the descriptors
1234 	 * already allocated for the transfer which just completed.
1235 	 */
1236 	for (desc = SLIST_FIRST(&dxs->dxs_descs); desc; desc = ndesc) {
1237 		ndesc = SLIST_NEXT(desc, d_link);
1238 		SLIST_INSERT_HEAD(&sc->sc_descs, desc, d_link);
1239 		sc->sc_free_descs++;
1240 	}
1241 
1242 	if ((dcsr & DCSR_BUSERRINTR) || dmac_continue_xfer(sc, dxs) == 0) {
1243 		/*
1244 		 * The transfer completed (possibly due to an error),
1245 		 * -OR- we were unable to continue any remaining
1246 		 * segment of the transfer due to a lack of descriptors.
1247 		 *
1248 		 * In either case, we have to free up DMAC resources
1249 		 * allocated to the request.
1250 		 */
1251 		sc->sc_active[channel] = NULL;
1252 		dmac_free_channel(sc, DMAC_PRI(dxs->dxs_priority), channel);
1253 		dxs->dxs_channel = DMAC_NO_CHANNEL;
1254 		if (dxs->dxs_peripheral != DMAC_PERIPH_NONE)
1255 			dmac_reg_write(sc, DMAC_DRCMR(dxs->dxs_peripheral), 0);
1256 
1257 		if (dxs->dxs_segs[DMAC_DESC_SRC].ds_nsegs == 0 ||
1258 		    dxs->dxs_segs[DMAC_DESC_DST].ds_nsegs == 0 ||
1259 		    (dcsr & DCSR_BUSERRINTR)) {
1260 
1261 			/*
1262 			 * The transfer is complete.
1263 			 */
1264 			dxs->dxs_queue = NULL;
1265 			rv = 1u << DMAC_PRI(dxs->dxs_priority);
1266 
1267 			if (dxs->dxs_peripheral != DMAC_PERIPH_NONE &&
1268 			    --sc->sc_periph[dxs->dxs_peripheral].sp_busy != 0) {
1269 				struct dmac_xfer_state *ndxs;
1270 				/*
1271 				 * We've just removed the current item for this
1272 				 * peripheral, and there is at least one more
1273 				 * pending item waiting. Make it current.
1274 				 */
1275 				ndxs = SIMPLEQ_FIRST(
1276 				  &sc->sc_periph[dxs->dxs_peripheral].sp_queue);
1277 				KDASSERT(ndxs != NULL);
1278 				SIMPLEQ_REMOVE_HEAD(
1279 				   &sc->sc_periph[dxs->dxs_peripheral].sp_queue,
1280 				    dxs_link);
1281 
1282 				ndxs->dxs_queue =
1283 				    &sc->sc_queue[DMAC_PRI(dxs->dxs_priority)];
1284 				SIMPLEQ_INSERT_TAIL(ndxs->dxs_queue, ndxs,
1285 				    dxs_link);
1286 			}
1287 
1288 			(dxs->dxs_done)(&dxs->dxs_xfer,
1289 			    (dcsr & DCSR_BUSERRINTR) ? EFAULT : 0);
1290 		} else {
1291 			/*
1292 			 * The request is not yet complete, but we were unable
1293 			 * to make any headway at this time because there are
1294 			 * no free descriptors. Put the request back at the
1295 			 * head of the appropriate priority queue. It'll be
1296 			 * dealt with as other in-progress transfers complete.
1297 			 */
1298 			SIMPLEQ_INSERT_HEAD(
1299 			    &sc->sc_queue[DMAC_PRI(dxs->dxs_priority)], dxs,
1300 			    dxs_link);
1301 		}
1302 	}
1303 
1304 	return (rv);
1305 }
1306 
1307 static int
dmac_intr(void * arg)1308 dmac_intr(void *arg)
1309 {
1310 	struct pxadmac_softc *sc = arg;
1311 	uint32_t rv, mask;
1312 	u_int chan, pri;
1313 
1314 	rv = dmac_reg_read(sc, DMAC_DINT);
1315 	if ((rv & DMAC_DINT_MASK) == 0)
1316 		return (0);
1317 
1318 	/*
1319 	 * Deal with completed transfers
1320 	 */
1321 	for (chan = 0, mask = 1u, pri = 0;
1322 	    chan < DMAC_N_CHANNELS; chan++, mask <<= 1) {
1323 		if (rv & mask)
1324 			pri |= dmac_channel_intr(sc, chan);
1325 	}
1326 
1327 	/*
1328 	 * Now try to start any queued transfers
1329 	 */
1330 #if (DMAC_N_PRIORITIES > 1)
1331 	if (pri & (1u << DMAC_PRIORITY_HIGH))
1332 		dmac_start(sc, DMAC_PRIORITY_HIGH);
1333 	if (pri & (1u << DMAC_PRIORITY_MED))
1334 		dmac_start(sc, DMAC_PRIORITY_MED);
1335 	if (pri & (1u << DMAC_PRIORITY_LOW))
1336 		dmac_start(sc, DMAC_PRIORITY_LOW);
1337 #else
1338 	if (pri)
1339 		dmac_start(sc, DMAC_PRIORITY_NORMAL);
1340 #endif
1341 
1342 	return (1);
1343 }
1344